2016 American College of Rheumatology/European League Against Rheumatism criteria for minimal, moderate, and major clinical response in adult dermatomyositis and polymyositis

Abstract

Objective Develop response criteria for adult dermatomyositis (DM) and polymyositis (PM). Methods Expert surveys, logistic regression, and conjoint analysis were used to develop 287 definitions using core set measures (CSM). Myositis experts rated greater improvement among multiple pair-wise scenarios in conjoint analysis surveys, where different levels of improvement in two CSM were presented. The PAPRIKA (Potentially All Pairwise Rankings of All Possible Alternatives) method determined relative weights of CSM and conjoint analysis definitions. Performance characteristics of definitions were evaluated on patient profiles using expert consensus (gold standard) and were validated using a clinical trial. Nominal group technique was used for consensus. Results Consensus was reached for a conjoint analysis–based continuous model using absolute percentage change in CSMs (physician, patient, and extra-muscular global activity, muscle strength, health assessment questionnaire and muscle enzymes). A Total Improvement Score (0–100), determined by summing scores in each CSM, was based on the improvement and relative weight of each CSM. Thresholds for minimal, moderate, and major improvement were ≥20, ≥40, and ≥60 points in the Total Improvement Score. The same criteria were chosen for juvenile DM with different improvement thresholds. Sensitivity and specificity in DM/PM patient cohorts were 85% and 92%, 90% and 96%, and 90% and 96% for minimal, moderate, and major improvement, respectively. Definitions were validated in trial analysis for differentiating the physician rating of improvement (P<0.001). Conclusion The response criteria for adult DM/PM was the conjoint analysis model based on absolute percentage change in six CSMs, with thresholds for minimal, moderate, and major improvement.

Current Classification and Management of Inflammatory Myopathies

“…The extra muscular disease activity is an important component of the core set since it reflects tissue damage of joints, lung, skin, heart, or the gastrointestinal system [ 168 ]. Recently, the core set measures were transformed into a numeric scale and weighted depending on their impact on the final score; this composite score was officially accredited as “response criteria” by the American College of Rheumatology (ACR) and the European League Against Rheumatology (EULAR) for adult myositis [ 169, 170 ] as well as for juvenile myositis [ 171, 172 ]. Manual muscle testing of a group of muscles (MMT-6 or MMT-8) is an important component of this longitudinal assessment in myositis and should be performed by the physician at each clinical visit.…”

The host defense peptide LL-37 a possible inducer of the type I interferon system in patients with polymyositis and dermatomyositis

“…A new set of improvement criteria, 2016 American College of Rheumatology/European League Against Rheumatism criteria for minimal, moderate, and major clinical response in adult dermatomyositis and polymyositis, were published based on the core set measures of IMACS describing myositis disease activity [24,25]. Total improvement score (range 1-100) is calculated by adding scores of the six core set disease activities of IMACS, and ≥ 20, ≥ 40, ≥ 60 represents minimal, moderate, and major improvement, respectively.…”

“…Total improvement score (range 1-100) is calculated by adding scores of the six core set disease activities of IMACS, and ≥ 20, ≥ 40, ≥ 60 represents minimal, moderate, and major improvement, respectively. This improvement criteria use a continuous quantitative definition, which not only defines patients qualitatively, but also quantitatively [25]. The exact scores representing the improvement of patients could also be used to calculate the correlations between the improvement and other clinical or molecular variables.…”

“…Myositis experts voted to agree on the new definition also to lay the foundation of general application of these criteria in the future. These criteria are also suitable for both adult DM/PM and also JDM patients except for different thresholds, which help the parallel comparisons of different studies [25].…”

New Myositis Classification Criteria—What We Have Learned Since Bohan and Peter

“…In the hope of transitioning to a more contemporary classification, the EULAR/ACR criteria have been developed and validated with a robust methodology, an improvement over previous criteria sets. The new IIM classification criteria are a valuable addition to the myositis disease activity core measures endorsed by IMACS and the recently published ACR/EULAR adult PM/DM and juvenile DM response criteria [ 50 •, 56 , 57 ••, 58 ••]. In the future, these new classification and response criteria should continue to evolve and reflect epidemiologic and molecular knowledge advances on IIM.…”